InstaLock for Windows Phone 8 lets you set Instagram Photos as lockscreen on hourly basis.
You can choose from Popular Images or follow a specific user or tag.
Have an Instagram account? You can also set your Instagram Photos as lockscreen. InstaLock also lets you browse through Instagram Photos and save or set a particular photo as lockscreen.
The App is Windows Phone 8 only and costs $0.99. Trial version is fully functional with Ads. Download the app here or use the QR Code below.